Corvus (weapon)
The corvus (meaning "crow" or "raven" in Latin) was a Roman military boarding device used in naval warfare during the First Punic War against Carthage.
In Chapters 1.22-4-11 of his History, Polybius describes this device as a bridge 1.2 m (4 ft) wide and 10.9 m (36 ft) long, with a small parapet on both sides. The engine was probably used in the prow of the ship, where a pole and a system of pulleys allowed the bridge to be raised and lowered. There was a heavy spike shaped as a bird's beak on the underside of the device. The spike was designed to pierce the enemy ship's deck when the boarding-bridge was lowered. This allowed a firm grip between the vessels and a route for the legionaries to cross to the other ship.
In the 3rd century BC, Rome was not a naval power, and had little or no experience in war at sea. Before the First Punic War, the Roman Republic had not campaigned outside the Italian Peninsula. The Republic's military strength was on land, and her greatest assets were the discipline and courage of her soldiers. The boarding-bridge allowed her to use her marines against the superior Carthaginian naval skills. The Romans' application of boarding tactics worked; they won several battles, most notably those of Mylae, Sulci, Tyndaris, and Ecnomus.
Despite its advantages, the boarding bridge had a serious drawback: it could not be used in rough seas since the stable connection of two working ships endangered each other's structure. Operating in rough seas, the device became useless and was abandoned. Contrary to some speculation, it does not appear that the weight of the device threatened the stability of the ship when the bridge was raised; according to Bonebaker, Professor of Naval Architecture at Delft, with the estimated weight of one ton for the boarding bridge, it is "most probable that the stability of a quinquereme with a displacement of about 250 m3 (330 cu yd) would not be seriously upset".
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